In the presently established manners of dispensing printing press ink, the ink may be commonly taken from a rigid container and dispensed into the fountain, and this can be done manually. In some of the prior art arrangements, the ink would be supplied to the press fountain manually, and the original ink containers would necessarily be left for the ink therein to dry out and not be usable. This, and other manners, represent the prior art and are found to be time consuming, unclean, wasteful with ink, and requiring constant monitoring by the press operator. In some instances, such as that shown in U.S. Pat. 4,699,054, there is the utilization of a bag of ink which feeds, but only by gravity, into a cartridge for the movement of the ink. Printing press ink does not readily respond to gravity flow, and in the aforesaid prior art, the cartridge and its connecting parts were necessarily employed and normally become wasted parts since they cannot be cleaned and reused.
The prior art is also aware of the employment of a sensor in the printing press ink fountain for determining the level of ink in-the fountain, and the sensor may be connected to a computer which controls an ink pump for supplying ink to the fountain. Such an arrangement is that which is shown in U.S. Pat. No. 4,852,604. In that arrangement, the ink is dispensed from tanks which are connected to the fountain, and pumps are employed for moving the ink from the tank to the fountain. The arrangement is such that the tanks must be completely emptied after each print run, or the remaining ink in the tank is to be wasted, and the tanks must be specially cleaned, including the connecting lines, before refilling the tank and, of course, before changing the color of the ink.
The present invention improves upon the prior art in that it provides a method and apparatus for dispensing ink to a printing press and doing so in a manner wherein the ink is initially contained in a flexible dispensing bag and is directed to the press fountain in a simplified, automated, and reliable arrangement. More specifically, the ink is dispensed by means of sensing the level of ink in the fountain and correspondingly activating a dispenser which causes the ink to flow from the flexible bag and into the fountain. As such, there is no requirement for pumps, valves, and also no requirement for manual operations and attendance because the entire arrangement is automated, and uses only a solenoid valve.
The present invention also includes a provision and utilization of a flexible ink-containing bag which renders the entire arrangement self-contained and thus clean with regard to the handling of the ink. Other parts of the system are also arranged for easy cleaning and thus expediting the maintaining of the equipment in clean condition and the changing of the operation to different colors of ink.
Still further, the present invention provides for the handling of printing press ink in a manner wherein the operation can be interrupted at any time and the quantity of ink yet to be dispensed, such as that in the flexible bag, can be readily preserved, including the removal of the bag from the remainder of the apparatus. Also, the present arrangement is such that bags of varying sizes can be accommodated. Also, the bags can be completely evacuated in only the normal course of operation.
Another specific object is the arrangement of the dispensing system wherein the system transporting the ink can be readily cleaned at the appropriate time, and such convenience is established by having the components of the system easily disassembled for the cleaning.
Additionally, an object is to provide a flexible bag supplying the ink, and to arrange that the bag is evacuated of its ink directly into the ink fountain, that is, without the need for any interconnecting parts or method steps between the bag and the fountain.
Further, there is the provision of the parts and method steps whereby an ink dispenser manifold is disposed directly above the fountain and distributes ink evenly into the fountain, and it utilizes a distribution nozzle outlet which restricts the ink flow to impart shear to the ink to improve flow by breaking the Thixotropic nature of printing ink. The Thixotropic nature of ink causes it to resist flow if it is stationary for a while, so it is preferred to pressurize it to initiate the flow, otherwise, it has a very high vicosity.
Also, the arrangement is such that there is a direct indication of the quantity of the ink in the bag, at any point in the operation. Further, when no further ink is to be moved through the system, then there can be an evacuation of the remaining ink and thereby preliminarily clean or evacuate the ink from the system simply by utilizing the system in its normal arrangement.